Dyspnea (including thoracentesis)


Definition:
Dyspnea is defined as a sensation of difficult or uncomfortable breathing. The symptom is highly prevalentable among cancer patients with and without direct lung involvement.

Dyspnea is believed to be multifactorial, with central, peripheral, and cognitive/emotional components. The respiratory center in the medulla coordinates the activity of the diaphragm, the intercostal muscles, and accessory muscles of respiration. It receives information from central and peripheral chemoreceptors, peripheral mechanoreceptors, and the cerebral cortex. Respiratory effort, hypercapnia, hypoxia, pulmonary stretch, pulmonary irritants, and mismatch between what the brain expects and the feedback it receives are all variables that play a role in dyspnea.

Dyspnea in cancer patients may be due to the direct or indirect effects of tumors, the effects of anticancer therapy, or may be unrelated to the cancer. Possible specific etiologies of dyspnea are listed in Table 1. Despite this extensive list, few studies have systematically categorized the causes of dyspnea in cancer patients.





Patient presents with these symptoms:
  • Patient report of difficulty/uncomfortable breathing - Gold standard of assessment
  • Normal temperature
  • Tachycardia
  • Shallow increased respirations
  • Increased fatigue
  • Decreased oxygen saturation (in the upper 80’s)
  • Arterial blood gas measurements frequently do not correlate with the subjective experience of dyspnea (
    For example, patients may be hypoxic but not dyspneic or dyspneic but not hypoxic.)
  • Absent breath sounds
  • Anxious
  • Distressed

Diagnostics:
  • Chest x-ray shows pleural effusion
  • arterial blood gas determinations
  • pulmonary function tests
  • computed tomography scans
  • echocardiograms
  • ventilation-perfusion scans.

Treatment:
After risk-benefit analysis, treatment should be directed at alleviating reversible causes when possible, without neglecting concurrent symptomatic treatment.
  • Direct tumor symptoms can potentially be treated with resection, chemotherapy, or radiation therapy.
  • Obstruction can be treated locally with laser therapy, cryotherapy, or stenting.
  • Malignant pleural effusions can be drained by thoracentesis. Fluid drainage may improve the mechanical ability of the respiratory muscles to relieve dyspnea.

If attempts to control reversible causes is not effective, or if reversible cause is present, symptomatic control of dyspnea may be needed:
  • Opioids - first-line therapy
  • Anxiolytics
  • Oxygen
  • Cognitive Behavioral therapy

Thoracentesis: A procedure performed to remove the fluid from the space between the lining of the lungs and the wall of the chest

Performed under ultrasound.

A needle is placed through the skin and muscles of the chest wall into the space around the lungs, called the pleural space. Fluid is collected and may be sent to a laboratory for testing.

The procedure:
No special requirements are needed for the patient
The patient needs to be educated on the procedure, and also needs to understand that he/she cannot cough or move during the procedure to prevent injury to the lung

Complications:
  • Bleeding
  • Fluid buildup
  • Infection
  • Pneumothorax
  • Pulmonary edema
  • Respiratory distress

Other teachings for Dyspnea:
Teach relaxation techniques
Teach pursed-lip breathing




References:
http://www.nlm.nih.gov/medlineplus/ency/article/003420.htm
http://imaging.ubmmedica.com/cancernetwork/journals/oncology/images/o0206bt1.gif
http://www.psychiatrictimes.com